Long-haul truck drivers typically idle their engines at truck stops or other locations to maintain power to the sleeping compartment of the tractor and, in colder climates, to keep the motor warm to avoid starting problems that might delay delivery of the cargo. Further, some trucks have a trailer that includes a refrigeration unit that requires constant power to avoid spoilage of cargo, which requires power from a diesel powered Trailer Refrigeration Unit (TRU), external power or a separate generator. External power is generally known as shore power.
Federal hours-of-service rules regulate mandatory rest periods for truck drivers, but state and local laws, in an effort to reduce fuel consumption and toxic emissions, may limit the time trucks and buses can idle. Therefore, there is a need to have an easy way for truck drivers to connect to shore power to maintain power to the sleeping compartment of the tractor and accessories used to keep the truck engine warm, as well as power refrigeration units on trailers that have them.
Truck drivers typically prefer to back into parking spaces so that they can easily pull out with other vehicles parked in close proximity, thereby reducing the risk that they will hit one of those vehicles. Also, when unloading a trailer, trucks are often backed towards a building and into a loading dock. In either situation, an external power source is then located at the rear of the truck. However, truck connections for external power are typically located on the tractor, which is at the front of the truck. In trailers with refrigeration units, which are typically located at the front of the trailer, connections to external power is usually located on the refrigeration unit itself or close to it. Both situations require a truck driver who backs into a parking space or loading dock to carry a long extension cord to run the length of the trailer to connect to an external power source. Trailers can be sixty feet long, resulting in a large and heavy extension cord that is difficult to handle. Further, a lose extension cord lying on the ground along the trailer can be a hazard for those walking by the truck as well as a hazard for the truck driver if the extension cord is lying in water or debris on the ground.